This project consists of an ultrastructural and biochemical investigation of secretory processes in the ventral prostate of the male rat in a tissue-slice system and in vivo. Gland slices are incubated in a modified Krebs-Ringer buffer equilibrated with 96% 02 and 5% CO2 at 37 degrees with constant shaking. In vitro secretion is followed biochemically by assaying samples of medium collected at regular intervals for marker enzymes of cytoplasmic organelles, e.g., acid phosphatase (lysosomes), succinate dehydrogenase (mitochondria), glucose-6-phosphatase (endoplasmic reticulum), and for citric acid and spermidine. A number of agents, including dihydrotestosterone, and selected neurotransmitters and blockers, will be studied for their effects on in vitro secretion. The ultrastructural effects of these agents in prostatic epithelium will be investigated by electron microscopy in vitro and in vivo. BIBLIOGRAPHIC REFERENCES: Koenig, H., Lu, C.Y. and Bakay, R., Testosterone and dibutyryl cyclic AMP stimulate protein and lysosomal enzyme secretion in rat seminal vesicle. Biochem J. 158, 543-547, 1976. Koenig, H., Lu, C.Y. and Bakay, R., Lysosomal enzyme secretion in rat ventral prostate. Proceedings of the 3rd International Symposium on Intercellular protein Catabolism, Acta Biol. Med. Germ., 1977, in press.